Compilare: user.cpp: In function ‘int gcd(int, int)’: user.cpp:8:28: warning: operation on ‘b’ may be undefined [-Wsequence-point] a = a + b - (b = a); ^ user.cpp: In function ‘int main()’: user.cpp:22:25: warning: too many arguments for format [-Wformat-extra-args] scanf("%d",&a,&b); ^ user.cpp:16:36: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("euclid2.in","r",stdin); ^ user.cpp:17:38: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("euclid2.out","w",stdout); ^ user.cpp:19:19: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d",&t); ^ user.cpp:22:26: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d",&a,&b); ^